External stimulus. The rain is something out of your control while you're waiting. Rain is not something you are doing nor is it a response to you waiting for the bus.
The water repellant properties of waxes is very useful in the leaves of some plants, in the feathers of birds and also in cuticle of insects. Waxes in plant leaves reduce the amount of water that is lost by the leaves. The wax that is present in the birds' feather prevent them from getting wet with water.
I belive the answer would be "A" because the cell would be trying to delute the solution on the outside, and strenghting the solution on the inside.
No, that is because a living thing would need to reproduce, and also include living cells. When you remove the pedals, it will rot after a bit and then eventually die completely.
